In the simplest terms, power generators convert mechanical energy to electrical energy via the interaction of rotating magnetic fields and coils of wire. A multitude of alternating current (AC) generator systems, for example, have been developed with various means of providing interaction between magnetic fields and coils of wire. For example, an AC generator system may include an auxiliary power unit (APU) generator driven by a gas turbine engine to provide a secondary power source to an aircraft. The AC generator system is typically required to maintain a constant output frequency in order to properly drive electrical systems connected AC generator system output. However, the rotational speed of the drive shaft can vary during operation, thereby varying the respective output frequencies of the APU generator. Variable speed AC generator systems have been developed, which include large exciter assemblies due to the low frequency AC power required to be injected into the main generator field winding. Consequently, the large size of the exciter significantly increases the overall size and weight of conventional variable speed AC generator systems. Moreover, conventional variable speed AC generator systems drive the voltage/frequency controller with rotor mounted power converters via rotating signal transformers. Consequently, conventional variable speed AC generator systems require additional rotating signal transformers to electrically start the engine.